New York AGRICULTURAL EXPERIMENT STATION. 181 
‘These results are presented below in tabulated form. 
Taste II1.—SuHowine ReEsutts or ACTION oF FREE ALKALI IN Soap 
ON FOLIAGE. 
Extent oF InJury DoNE TO FoLIAGE BY FREE ALKALI IN SOAP. 
Kind of | When When Percentage of Free Alkali in Soap from which Solutions 
: foliage. | treated. | examined. were made. 
0.75 1 2 5 | 10 11.23 20 50 
| 
Apple June 22)June 24 None None |None |None Some = 
Apple June. 22'June 25|'None |None |None |None Some 
Pear June 22/June 24\None |None |None |None None = 
Pear June 22) June 25,None |None |None |None Slight 
Plum June 22 June 24\'Nene None |None |None |None 
Plum June 22'June 25|None |None |None |None |None 
Currant |June 22|June 24 None |None |None |None |None | —— | ——— 
Currant |June 22)June 25 None |None |None |None |None 
None |None Some |Some |Some 
None |None |Some |Some (Serious 
None |None ‘None ‘None {Slight 
None None Slight |Some ‘Serious 
[None |None |None 
None |None |None |None (Slight 
None |None |None |None |None 
None |None |Some Some (Serious 
Apple June 23\June 24 None 
Apple June 23)June 25) None 
Pear June 23\June 24|None 
Pear June 23 June 25) None 
Plum June 23)June 24|)None 
Plam June 23 June 25|None 
Cherry j|June 23) June 24|None 
Cherry |June 23)June 25 None 
Apple June 24|June 27 if 
Pear. June 24\June 27 =— 
Plum June 24\June 27 —— he 
HTH 
(INH 
Currant |June 24) June 27 = | 
Cherry |June 24) June 27| —— == | == 
Peach June 24\June 27; —— 
The results of the experiments described. above indicate that 
the presence of free alkali to the extent of five per ct. in soap 
does not injure foliage when the soap is made into a solution of 
one pound of soap in seven gallons of water. Comparatively 
little harm is done even when the amount of free alkali in a 
soap amounts to 10 per ct., the soap solution being of the same 
degree of dilution. It can readily be seen, therefore, that home- 
made soap No. 1, containing less than one per ct. of free alkali, 
can be safely used on all the varieties of foliage experimented 
with and can also be relied upon to destroy plant lice, when used 
in the form of a solution of one pound of soap to seven gallons 
of water. 
COST OF MATERIALS USED IN HOME-MADE SOAP. 
Caustic soda of good commercial quality (74 per ct.) can be 
purchased from the Penn Chemical Co., 1522 Washington avenue, 
Philadelphia, Pa., at about four cents a pound, f. o. b., put up in 
50-pound cans. Making liberal allowances for freight and any 
incidental expenses, the cost of caustic soda should not exceed 
